1. Field of the Invention
The present invention relates generally to an identification code input board employable for an electrical lock, an activating unit for electrical equipment or the like. More particularly, the present invention relates to an identification code input board (hereinafter referred to simply as an input board) having substantially improved characteristics.
2. Description of the Related Art
When an electrical lock is locked or unlocked, usually, an identification code is first inputted into an input board placed on the inlet side of a door, and thereafter, a predetermined number of handling steps are executed by a user's hand.
Usually, the input board includes a plurality of light emitting diodes (hereinafter referred to simply as LEDs) adapted to display ten arabic numerals 0 to 9 and two control codes in each of, e.g., twelve display sections arranged in the form of 4 lines X 3 rows, and each display is fed to a control circuit in the electrical lock in the form of a code via a transparent key switch panel superimposed on the LED by depressing one of keys on the key switch panel with a user's finger.
As the input board is repeatedly used for a short time, a problem arises in that the content of the identification code is undesirably perceived by a third person in the presence of sweat and/or oils adhering to the key switch panel. In addition, there is a possibility that the content of the identification code is likewise undesirably perceived by the third person based on a functional injury (e.g.-wear), a frictional scratches or the like caused on the key switch panel as the input board is repeatedly used for a long time. Thus, since the conventional input board is constructed in the above-described manner, there is a danger that the content of the identification code is readily known by a third person based on mathematic permutations and combinations made by himself for searching for the identification code specifically allocated to the input board.
To obviate the foregoing malfunctions, a proposal has been made with respect to an input board which is constructed such that an arrangement pattern of codes on a display panel is caused to randomly or regularly vary every time an actuating unit for actuating the electrical equipment, such as an electrical lock, is activated, and the thus proposed input board is put in practical use.
With the proposed input board, it is certain that there does not arise a malfunction that the content of the identification code specifically allocated to the input board is undesirably perceived by a third person based on a functional injury, scratches or the like caused on the front surface of a key switch panel as the input board is repeatedly used for a long time. However, since the display position of the identification code on the key switch panel is caused to vary every time an actuation unit, e.g., an electromagnetic actuator or the like for actuating the electrical lock, is activated, it is inconvenient to use the prior art input board.